davenport
Halfway is the western part of the Denver metropolitan area. I'd break that trip up into thirds.
K
about 133 miles
Buchanan, OH
North Hartland, NY is the halfway point.
The nearest town to the halfway point is South Wayne, WI. It is 117.98 miles from Cedar Rapids, IA and 117.69 miles from Kenosha, WI. It would take 2 hours 35 mins to go from Cedar Rapids to South Wayne and near enough the same from Kenosha to South Wayne.
about 590 miles
Roanoke Rapids, NC
London, Ontario in Canada.
Liberal, KS
Forsyth, MT
around Cedar Rapids, IA